•The surface geothermal water chemistry and alteration mineralogy associated with rhyolitic rocks at Torfajökull central volcano, Iceland was studied.•The evolution of reservoir geothermal fluids to ...surface were quantified, the processes being boiling, mixing, and water–rock interaction.•The surface geochemical exploration methods developed and applied here are suitable for any geothermal system in order to explore geochemical processes occurring in active geothermal systems.
The surface geothermal water chemistry and alteration mineralogy associated with rhyolitic rocks at Torfajökull central volcano, Iceland was studied. The geothermal waters ranged in pH and temperature from 2.33 to 9.77 and 6–98°C, respectively, and was characterized by variable alteration products including amorphous silica, quartz, hematite, goethite, kaolinite, elemental sulfur, pyrite, anatase, montmorillonite. alunite, amorphous iron silicates, pyrite, goethite, hematite and illite. The chemical composition of these waters and the associated mineralogy is influenced by several processes occurring from the geothermal reservoir to the surface including boiling, mixing, degassing, oxidation and water–rock interaction. In order to quantify these processes and explain the observed geothermal surface water composition and mineralogy, a geochemical model was applied that involved three steps: (i) defining the composition of the end-member fluid types present in the system, (ii) applying a mixing model based on conservation of non-reactive elements and enthalpy (temperature) and (iii) quantifying the process of progressive fluid–rock interaction and secondary mineral formation in the surface zone. The model may be applied to any geothermal system. Geothermal waters at Torfajökull represent either a mixture of non-thermal water and condensed steam with insignificant fraction of boiled reservoir water or boiled reservoir water that has been mixed. Two types of steam-heated waters were observed, acid and carbonate rich, the difference thought to be related to the boiling process. Steam-heated carbonate waters are formed from <10% steam originated by boiling and phase segregation at >200°C followed by mixing with non-thermal water at shallow depth whereas steam-heated acid waters are formed upon extensive boiling and steam condensation and mixing with non-thermal surface in the surface zone. The surface alteration mineralogy and associated elemental mobility is largely influenced by the formation mechanism and chemistry of the geothermal surface water in the surface zone. At acid pH and under oxidized conditions Na, K, Mg and Ca were observed to be mobile and leached out whereas Fe, Ti and to a less extent Si, were retained in the alteration product forming amarphous silica, kaolinite, anatase and pyrite as well as some smectites and sulfates. For steam-heated carbonate waters, Na and K were observed to be mobile whereas Fe and Si are retained in amorphous silica, ferrihydrites and iron rich silicates. Carbonates were not calculated or observed to form associated with carbonate springs. Magnesium, Ca and K were observed to be mobile at pH<6 whereas they are quantitatively retained into smectites and eventually also zeolites and carbonates with increasing pH. As a consequence, the mobility of Mg and K and to a less extent Ca and Na are greatly reduced under alkaline conditions. Based on the above, the key factors controlling the fluid–rhyolite interaction under surface geothermal conditions (∼100°C) are acid supply, oxidation state and extent of reaction. The surface geochemical exploration methods developed and applied here are suitable for any geothermal system in order to explore geochemical processes occurring in active geothermal systems including boiling and fluid mixing, fluid and elemental sources, reservoir fluid properties and when applied before and during geothermal exploitation and utilization how these may have changed in nature with time.
A group of Early-Career Researchers (ECRs) has been given a mandate from the European Committee for Future Accelerators (ECFA) to debate the topics of the current European Strategy Update (ESU) for ...Particle Physics and to summarise the outcome in a brief document 1. A full-day debate with 180 delegates was held at CERN, followed by a survey collecting quantitative input. During the debate, the ECRs discussed future colliders in terms of the physics prospects, their implications for accelerator and detector technology as well as computing and software. The discussion was organised into several topic areas. From these areas two common themes were particularly highlighted by the ECRs: sociological and human aspects; and issues of the environmental impact and sustainability of our research.
Chest computed tomography (CT) imaging has become indispensable for staging and managing coronavirus disease 2019 (COVID-19), and current evaluation of anomalies/abnormalities associated with ...COVID-19 has been performed majorly by the visual score. The development of automated methods for quantifying COVID-19 abnormalities in these CT images is invaluable to clinicians. The hallmark of COVID-19 in chest CT images is the presence of ground-glass opacities in the lung region, which are tedious to segment manually. We propose anamorphic depth embedding-based lightweight CNN, called Anam-Net, to segment anomalies in COVID-19 chest CT images. The proposed Anam-Net has 7.8 times fewer parameters compared to the state-of-the-art UNet (or its variants), making it lightweight capable of providing inferences in mobile or resource constraint (point-of-care) platforms. The results from chest CT images (test cases) across different experiments showed that the proposed method could provide good Dice similarity scores for abnormal and normal regions in the lung. We have benchmarked Anam-Net with other state-of-the-art architectures, such as ENet, LEDNet, UNet++, SegNet, Attention UNet, and DeepLabV3+. The proposed Anam-Net was also deployed on embedded systems, such as Raspberry Pi 4, NVIDIA Jetson Xavier, and mobile-based Android application (CovSeg) embedded with Anam-Net to demonstrate its suitability for point-of-care platforms. The generated codes, models, and the mobile application are available for enthusiastic users at https://github.com/NaveenPaluru/Segmentation-COVID-19.
An adequate maternal cobalamin status is crucial for fetal and infant neurodevelopment. Pregnancy-induced physiologic changes make evaluation of maternal cobalamin status in pregnancy difficult.
We ...have investigated maternal cobalamin status during pregnancy in order to establish a maternal cobalamin concentration which secures an optimal infant cobalamin status during the first 6 mo of life.
In an observational, prospective study, markers of cobalamin status including serum cobalamin, plasma total homocysteine (tHcy), and plasma methylmalonic acid (MMA) were assessed in healthy pregnant women (n = 114) from week 18 of pregnancy through 6 mo postpartum and related to infant cobalamin status at 6 mo. Healthy, never-pregnant women aged 18–40 y (n = 123) were included as controls.
Compared to controls, all markers of cobalamin status were lower in pregnant women. Median serum cobalamin concentration progressively decreased from week 18 to week 36 of pregnancy (356 to 302 pmol/L, P < 0.001) and increased by >40% by 6 wk postpartum (518 pmol/L). The metabolic markers increased from week 18 of pregnancy to 6 wk postpartum: median plasma tHcy 3.9 to 7.7 μmol/L (P < 0.001), and MMA 0.13 to 0.17 μmol/L (P < 0.001). The serum cobalamin concentration of infants at age 6 mo correlated with maternal serum cobalamin concentration during pregnancy and postpartum (rho = 0.36–0.55, P < 0.001). A maternal serum cobalamin concentration <394 pmol/L during week 18 of pregnancy was associated with an increased risk (OR: 4.2; 95% CI: 1.5, 11.5) of infant biochemical cobalamin deficiency at 6 mo (defined as tHcy ≥6.5 μmol/L).
The maternal serum cobalamin concentration in early pregnancy is a strong predictor for later maternal and infant cobalamin status. To secure an optimal infant cobalamin status during the first 6 mo of life, we recommend a maternal serum cobalamin concentration >394 pmol/L at week 18 of pregnancy. This should be confirmed in an intervention study. This trial was registered at clinicaltrials.gov as NCT03272022.
Exercise during cancer treatment improves cancer‐related fatigue (CRF), but the importance of exercise intensity for CRF is unclear. We compared the effects of high‐ vs low‐to‐moderate‐intensity ...exercise with or without additional behavior change support (BCS) on CRF in patients undergoing (neo‐)adjuvant cancer treatment. This was a multicenter, 2x2 factorial design randomized controlled trial (Clinical Trials NCT02473003) in Sweden. Participants recently diagnosed with breast (n = 457), prostate (n = 97) or colorectal (n = 23) cancer undergoing (neo‐)adjuvant treatment were randomized to high intensity (n = 144), low‐to‐moderate intensity (n = 144), high intensity with BCS (n = 144) or low‐to‐moderate intensity with BCS (n = 145). The 6‐month exercise intervention included supervised resistance training and home‐based endurance training. CRF was assessed by Multidimensional Fatigue Inventory (MFI, five subscales score range 4‐20), and Functional Assessment of Chronic Illness Therapy‐Fatigue scale (FACIT‐F, score range 0‐52). Multiple linear regression for main factorial effects was performed according to intention‐to‐treat, with post‐intervention CRF as primary endpoint. Overall, 577 participants (mean age 58.7 years) were randomized. Participants randomized to high‐ vs low‐to‐moderate‐intensity exercise had lower physical fatigue (MFI Physical Fatigue subscale; mean difference −1.05 95% CI: −1.85, −0.25), but the difference was not clinically important (ie <2). We found no differences in other CRF dimensions and no effect of additional BCS. There were few minor adverse events. For CRF, patients undergoing (neo‐)adjuvant treatment for breast, prostate or colorectal cancer can safely exercise at high‐ or low‐to‐moderate intensity, according to their own preferences. Additional BCS does not provide extra benefit for CRF in supervised, well‐controlled exercise interventions.
Total homocysteine (tHcy) measured in serum or plasma is a marker of folate status and a risk factor for cardiovascular disease.
Our objective was to investigate associations between tHcy and ...complications and adverse outcomes of pregnancy.
Plasma tHcy values measured in 1992-1993 in 5883 women aged 40-42 y were compared with outcomes and complications of 14492 pregnancies in the same women that were reported to the Medical Birth Registry of Norway from 1967 to 1996.
When we compared the upper with the lower quartile of plasma tHcy, the adjusted risk for preeclampsia was 32% higher odds ratio (OR): 1. 32; 95% CI: 0.98, 1.77; P for trend = 0.02, that for prematurity was 38% higher (OR: 1.38; 95% CI: 1.09, 1.75; P for trend = 0.005), and that for very low birth weight was 101% higher (OR: 2.01; 95% CI: 1.23, 3.27; P for trend = 0.003). These associations were stronger during the years closest to the tHcy determination (1980-1996), when there was also a significant relation between tHcy concentration and stillbirth (OR: 2.03; 95% CI: 0.98, 4.21; P for trend = 0.02). Neural tube defects and clubfoot had significant associations with plasma tHcy. Placental abruption had no relation with tHcy quartile, but the adjusted OR when tHcy concentrations >15 micromol/L were compared with lower values was 3.13 (95% CI: 1.63, 6. 03; P = 0.001).
Elevated tHcy concentration is associated with common pregnancy complications and adverse pregnancy outcomes.
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